Slewing Bearing/slewing ring bearing:the gear accuracy grade and the slewing bearing installation.
1.The gear accuracy grade of the slewing bearing and the feasibility and practicality of gear grinding
Generally, the slewing bearing can have external and internal teeth, and the tooth profile can be helical, half-tooth, tooth surface quenching, and tooth surface tempering. In order to improve the gear accuracy level, tooth grinding is a separate process. Special instructions in the drawings.
So, the subject of this article, talk about the gear accuracy grade of the slewing bearing and the feasibility and practicality of gear grinding.
It should be understood that the reason why the rotary slewing bearing is used as a rotating mechanism is that it is easy to maintain and maintain, and the other is to use the low-speed and heavy-duty characteristics of the slewing bearing. In other words, the slewing bearing itself, as a precision component, is actually a customized product.
The gear accuracy grade is usually indicated as 10/9/8, and 7/6/5 generally requires gear grinding. The gear grinding process is to achieve precise meshing and precise pointing and positioning. Most do not need to grind the teeth because the cost of grinding the teeth is very high.
2.Slewing Ring Bearing Installation Tips to Ensure Optimal Performance
While slewing ring bearings do perform heavy-duty functions often under the worst possible conditions, they must be treated as delicate instruments to ensure their accuracy and a long operating life. Following the installation procedures precisely is critical to ensuring the best possible performance.
While slewing ring bearings often perform heavy-duty functions under the worst possible conditions, they must be treated as delicate instruments to ensure their accuracy and a long operating life. Following the installation procedures precisely is critical to ensuring the best possible performance.
Slewing rings are vital to supporting heavy loads that must rotate to other positions in a precise manner. Devices that use slewing ring bearings include:
- Massive construction cranes
- Large solar tracking devices
- Some types of military armament
Since the rotation of the mechanism demands accuracy to assure effectiveness and safety, the installation of slewing ring bearings requires precision to expect proper operation.
Complying with every detail of the instructions is necessary for proper installation and function. Here are some installation tips that highlight the need for proper cre of this paowerful yet sensitive equipment.
MAKE SURE SLEWING RINGS ARE SHIPPED AND STORED PROPERLY
When the manufacturer prepares slewing ring bearings for shipment, they are lightly lubricated, wrapped for delivery and packed in individual specialized containers.
After receiving, store the unit in a clean, dry place in the original packing material until installation. Ensure that all areas around the slewing ring bearings are free of grit and dirt.
ALWAYS INSPECT FOR DISTORTION OR INTERFERENCE FROM DEBRIS
Each component of the slewing ring bearing must be clean, unobstructed by even the smallest foreign object and precisely oriented. Problems may arise during operation when friction or out-of-balance situations occur. The load may tend to concentrate in a particular area, creating a malfunction or improper wearing.
ENSURE SUPPORT SURFACES ARE LEVEL AND STRONG
The supporting surfaces must be machined smooth and perfectly level. They need to have sufficient strength to remain rigid during operation to eliminate any possible vibration or buckling due to imbalance.
CHECK THE RING CIRCULARITY
Protecting all elements of the slewing ring bearing is essential. If the circularity of the slewing ring is compromised during shipment and handling, the slewing drive will not work properly. Slewing ring bearings should be transported and stored in purpose-built crates and kept in a horizontal position at all times.
Ensure that the lifting apparatus or sling used is sufficiently robust and capable of lifting and holding the ring during installation. The external gear teeth must have protection to guard against damage from any collision with other surfaces.
Slewing ring equipment should not be in storage for longer than six months. The raceways must always be kept greased and free of rust.
PROPER SEALING AND LUBRICATION
Installers should specify integral seals on bearings and incorporate shrouding to protect the gears and bearings
As with most metal machine parts, proper lubrication is essential to smooth operations and long life. For slewing ring bearings and gears, this process is crucial. Equipment will come with operating instructions that will advise a recommended frequency for lubricating. Lubrication schedules depend on the type of equipment and the amount of use.
GEAR LUBRICATION
Immediately after assembly, you should lubricate the gear with either a brush or spray-on. Gear lube is recommended at least every three months, depending on how rigorously the equipment is used.
DOUBLE-CHECK THE INSTALLATION INSTRUCTIONS AND PERFORM TESTS BEFORE USE
Follow the manufacturer’s installation directions to the letter.
During installation, the slewing rings should be rotated while bolts are tightened to determine if any tight spots are developing. Also, recheck the bolt torque to identify any change due to settling.
Once the ring bearing is in position, check for any gear backlash and bearing torque before putting into operation. Deviations can indicate a problem with the mounting process.
3.SLEW RING BEARING LUBRICATION MISTAKES YOU SHOULD AVOID
Lubrication is essential for maintaining the integrity of a slew ring bearing. When bearings are optimally lubricated, they not only run safely, but also reduce the potential for premature failure. In order to ensure that slew ring bearings are properly maintained, the following mistakes should be avoided.
1. RELUBRICATING ON A YEARLY BASIS
Every slewing ring bearing has a recommended relubrication period and should be followed closely. These recommendations include the typical amount of lubrication needed for a reapplication as well as the most appropriate time interval.
It’s important to note that these recommendations can depend on application. For example, it is recommended that a slewing bearing is lubricated every 100 hours of operation. If the application involves continuous rotating, then the slewing bearing should be lubricated after 20 hours of continuous use. In addition, slewing bearings that are mounted on idle equipment, or those that live in storage, should be lubricated every six months.
Contact your slew ring manufacturer regarding your specific application in order to get the most accurate recommendation.
2. NOT USING THE PROPER LUBRICANT
Not all lubricants are created equal. If two incompatible greases are accidentally mixed, the reapplication process will be ineffective. The following chart depicts examples of recommended lubricants.
| Brand | Raceway | Gear |
| Exxon | Ronex MP | Surret Fluid |
| Castrol | Molub-Alloy 220 ES | Optimol Viscogen 0 |
| Mobil | Mobilux EP2 | Mobiltac 375NC |
| Texaco | Multifak EP2 | Crater 2x Fluid |
| Sunoco | Ultra Prestige 2 EP | |
| Shell | Alvania EP2 | Cardium Fluid M or H |
| Kluber | Centoplex 2 EP | Grafloscon C-SG 0 Plus |
| 76 Lubricants | Unoba EP2 | Gearite HDCF 4800 |
3. LUBRICATING TO THE POINT OF OVEFLOW
Although this is another misconception that varies by application, it is generally not recommended to lubricate slewing bearings so much so that the grease purges from the seal. The operating temperature and pressure within the cavity is likely to increase when excess grease is present. As a result, performance can be hindered.
4. ADDING ADDITIONAL GREASE WHENEVER BEARING MAKES NOISE
In some instances yes, your slewing bearing will need to be lubricated if it is making noise, but this is not true for all situations. Noisy slewing bearings can be a sign of internal damage as well. When internal damage occurs, extra lubricant will only provide temporary relief. Failure can occur if the root cause of the noise is not identified and remedied appropriately. If failure does occur, remove the slewing bearing as soon as possible and reach out to the bearing manufacturer to determine why the bearing was not compatible.
By avoiding the previously mentioned mistakes, you will be able to ensure that your slewing ring bearings are properly lubricated and performing as intended. If you have additional lubrication questions about your specific application, please reach out to us here.
